Parr 2, 1913] DICRANACEAE 99 
smooth, paler, rectangular, those at the angles broader, square to short-rectangular, sometimes 
inflated and 20 » or more wide, forming a rather distinct alar group; inner perichaetial leaves 
sheathing rather more than one half up: seta yellowish, about 8 mm. long: capsule from nearly 
straight and erect to curved and nodding, with or without struma, more or less contracted 
under the mouth and ribbed when dry; peristome-teeth reddish, divided to below the middle, 
vertically striate, papillose above, the inner articulations often distant, 35-40 4 apart; lid 
irregularly notched around the base, with an oblique beak about one half as long as the capsule; 
annulus large: spores rough, up to 20 p» in diameter. 
TYPE LocaLity: Germany. 
DIsTRIBuTION: Greenland to Alaska and south to New York, Lake Superior, and Montana; 
also in northern Europe. 
Inuusrrations: Hedw. Descer. 2: pl. 31, 32. 
Exsicc.: Drummond, Musci Am. 107; Sull. & . Musci Bor. Am. 45; 2. 58; 
Gin ecco ne. m Lesq. Musci Bor 5; ed. 2. 58; Macoun, 
3. Oncophorus Jenneri (Schimp.) R. S. Williams. 
Didymodon Jenneri Schimp.; Howie, Trans. Bot. Soc. Edinb. 9: 314. 1868. 
Cynodontium polycarpon laxirete Dixon, Handb. 73. 1896. 
Cynodontium laxirete Grebe, Hedwigia 40: Beibl. 106. 1901. 
Autoicous: male flower at the base of the perichaetium, of 2 ovate-lanceolate, more or less 
obtuse and costate, entire leaves, enclosing 6-8 antheridia and rather few paraphyses: plants 
in often extensive, not very compact, greenish tufts, with branching stems tomentose below and 
up to 5 cm. high or more: stem-leaves up to 6 mm. long by 0.6 mm. wide, mostly oblong- 
lanceolate, acute, keeled, spreading-flexuous, more or less recurved, subcrispate when dry, 
serrulate on the margin scarcely one fourth down, the borders flat toward the apex, more or 
less recurved below, of a single thickness of cells; costa scarcely percurrent, slightly serrulate 
on the back near the apex, in cross-section near the middle showing 4 guide-cells, a very small 
stereid-band above of only 2 or 3 cells, below a somewhat larger band, with the outer cells on 
both sides rather large; cells of the blade distinct, mostly quite smooth on both sides, the 
tipper ones square to short-rectangular, about 12 » wide, those toward the base paler, rec- 
tangular, up to 16 » wide and about 60 » long, those at the angles mostly narrower than toward 
the costa and 3-4 times as long as wide; perichaetial leaves similar to the upper stem-leaves, 
loosely clasping about one third up: seta about 1 cm. long, erect, yellowish: capsule about 2.5 
mm. long, oblong, nearly straight and erect, furrowed when dry and empty, not strumose but 
with a more or less distinct apophysis; peristome-teeth reddish, 80 » wide at the base, divided 
mostly more than one half down, vertically striate on the outer face, papillose above; annulus 
large, of 2 rows of cells; lid somewhat notched at the base, with an oblique beak about one 
half as long as the capsule: spores rough, up to 24 yw in diameter. 
TYPE LocaLIty: England. - ; 
DistRipurtI0on: Alaska, known only from Sheep Camp, Dyea,Creek (Williams 527); also in Scot- 
land and Germany. : 
ILLUSTRATION: Trans. Bot. Soc. Edinb. 9: pl. 5. 
! 
4, Oncophorus alpestris (Wahl.) Lindb. Musci Scand. 27. 1879. 
Dicranum alpestre Wahl. Fl. Lapp. 339. 1812. 
Cynodontium alpestre Milde, Bryol..Siles. 51. 1869. 
Autoicous: male flowers 1 or 2, mostly sessile, at or a little below the base of the perichae- 
tium, of about 4, ovate, acute, entire or subserrulate, ecostate, mostly smooth leaves enclosing few 
antheridia: plants in compact, green tufts, slightly radiculose below, with stems up to 1.5 cm high: 
leaves up to 1.5 mm. long, crispate when dry, lanceolate-linear with a usually broadly rounded 
apex, the borders papillose on the margins about two thirds down, recurved below, flat above 
and mostly of a single thickness of cells; costa vanishing in the apex, papillose on the back about 
oue half down, in cross-section below showing 4 guide-cells, the stereid-band mostly wanting 
on the ventral side, of few cells on the dorsal side, the outer ventral cells only about 2, the 
outer dorsal 9 or 10 in number; upper leaf-cells rather obscure, irregular, mostly 6-8 » wide 
by 8-10 long, sometimes roundish, highly mamillose on both sides about two thirds down 
the leaf, the lower cells smooth, more or less rectangular, those at the angles not differentiated; 
inner perichaetial leaves rather smaller than the upper stem-leaves, sometimes smooth and 
